Preparation of alkyl phenols from gasoline



PREPARATION OF ALKYL PHENOLS FROM GASOLINE April zo, 1954 ATTOR N EYSI Patented Apr. 20, 1954 UNITED vrs'rn'rurs PATENT cerros vrREPAlnrrIoN QF ALKYLPHENQLS FROM GASOLINE Warren W. Johnstone, Riverside, `Ill., ass'lig'nor to Universal Oil Products Company, Chicago, llll., a corporation of Delaware Application January 31, 1951, Serial No. 208,730

6 Claims. 1

This invention relates to the treatment of hydrocarbons and more particularly to a combination process wherein, by means of a series of mutually related and interdependent steps, phenols are liberated from a used alkaline treating solution and are incorporated into a liqueed gas stream prior to reaction thereof to form polymer. During the latter reaction the p-henols are reacted with a portion of the gases to formalkylated phenols. rlihe alkylated phenols possess desirable antioxidant properties and, in this manner, a, iina1 gasoline of improved Stability is obtained.

In one embodiment the present invention relates to a combination process which comprises treating gasoline containing phenolic compounds with an alkaline reagent to remove the phenols from the gasoline and retain them in the alkaline reagent, treating liquefied hydrocarbon gases containing rnore highly acidic components with said alkaline reagent containing phenol, whereby 'said pheno1 is transferred from the alkaline reagent to the liquefied gases and treating said gases containing phenol to form alkylated phenol and polymer.

From the description of the invention hereinbefore set forth, it is readily apparent that the novel combination process offers numerous advantages. Firstly, it provides for the further utilization of the treating reagent which previously had been employed to remove acidic components including phenols from gasoline and which otherwise would be discarded. Secondly, the invention provides for recovering the valuable phenols from the treating reagent and, thirdly, itlprovides for converting these phenols into more valuable alkylated phenols along with the polymerization of the hydrocarbon gases to form polymers.

The gasoline treated in the rst step of the process preferably is blended with the polymer' gasoline, and the blend thereby is stabilized against oxidative deterioration lby the inhibiting properties of the alkylated phenols.

The invention is further explained in conjunction with the accompanying diagrammatic ow drawing which illustrates one specific embodiment of the present invention.

Referring to the drawing, thel gasoline charge is introduced to the process through line I and is supplied to fractionator 2. Any suitable gasoline containing phenolic compounds may be utilized as the charge to the process and ygenerally will comprise cracked `gasoline containing sulfur compounds, such as mercaptans, hydrogen sulfide, etc. as well as phenols. It is understood 2 that reference to phenols herein includes phenolic Acompounds lwhich may contain alkyl sub'- stitu'ents thereof such 'as `'cresols, Xylenols, rvetc. However, in accordance with the present invention, the phenolic `'compounds vare alkylated in a later step of the process to form alkylated lphenol's which possess inhibiting properties and therefore will stop ror retard gum formation in the gasoline.

In the 'case here illustrated, fractionator 2 'prei-V -crably comprises a stabilizer wherebyy normally gaseous products, including hydrogen sulfide, eth-r ylene, ethano, propylene, propane and preferably at least 'a portion of the butylenes land butanes are 'separated 'and removed as an overhead fraction, to leave a gasoline product having vthe *desired vapor pressure. Fractionator 2 normally will be provided with suitable heating means `in the lower portion thereof, not illustrated, 'to ef- 20 fect the desired vaporization of the gaseous com ponents, and `also normally `will contain contacting means therein, not illustrated, such as bubble decks, trays, side to `side pans, etc. in order to obtain eilioi'ent 'fractionation therein.

Normally gaseous products, including Lgaseous ole-fins 'and hydrogen sulde, v"are withdrawn rfrom fractionator y2 'through line '3 and valve 4 'to "con.

denser v5. 'Condenser 5 may be cooled by am7 suitable means, including water .passed in in*- `direct heatexchange with'the hydrocarbons pass- The cooled and ing through the fcondenser. A partly condensed hydrocarbons pass from y'condenser 5 through line B and valve 'I into receiver B, wherein uncondensed gases separate from the condensate. 'The lcondensate may be 'withdrawn tractor 139, wherein it'passes in countercurrent y contact to caustic lsolution introduced through line 2:0. The drawing illustrates a `continuous ow process. However, it is understood that a batch type `operation lmay be employed. During 'contact `with the caustic solution in extractor I9, acidic components, vincluding mercaptans, phenols, etc. are removed 'from the gasoline l`vand are retained 1in 'the caustic -solution. vThe `gasesline -now substantially reduced in acidic componente is withdrawn from extractor fla through line 2l and may be removed from the process through valve 22. In a preferred embodiment of the invention, at least a portion of the treated gasoline is blended with the polymer gasoline in the manner to be hereinafter set forth.

Caustic is the preferred treating reagent and the caustic preferably is utilized asan aqueous solution of from about 5 to about 50 Baume gravity and still more preferably of from to about 30 Baume gravity. It is understood that any other suitable alkaline treating agent may be employed including potassium hydroxide, as

well as solutions containing solutizers including remaining uncondesed in receiver' 8 are With-' drawn therefrom through line 29 and are di-I rected to compressor 30 and the liquefied gases are then introduced into the lower portion of extractor 28, wherein the liqueiied gases pass in countercurrent contact with the caustic solution introduced through line 26. Here again, while a continuous flow is illustrated in the drawing, it is understood that a batch type operation may be employed. In another embodiment, receiver' 8 may be operated at a superatmospheric pressure high enough to retain the normally gaseous hydrocarbons in liquid phase and above the pressure employed in extractor i8. VThis embodiment will avoid the requirement for compressor 30.

The liquefied gases introduced through line 29 to extractor 28 Will contain hydrogen sulfide and loW boiling mercaptans including methyl mercaptan. During contact with the caustic solution containing phenols in extractor 28, the hydrogen sulde and methyl mercaptan, being more acidic than phenols, will liberate the phenols from the caustic solution and, in turn, will be retained in the caustic solution. Thus, this step provides the dual function of removing hydrogen suliide and,

light mercaptans from the gases and also. to transfer the phenols from the caustic solution to the liquefied gases. f

In order to retain thephenols in the normally gaseous hydrocarbons, it is an essential feature of the present invention that extractor 28 is operated under sumcient superatrnospheric pressure to maintain the normally gaseous hydrocarbons in liquid phase, which pressure may range from about 100 pounds to 500 pounds or more per square inch. The temperature employed preferably isfrom about 50 to about 150 F. and still more preferably from about 80 to about 120 F. Caustic solution containing sulfur lcompounds is Withdrawn from extractor 28 through line 3l and may be discarded from the process through valve l32. When desired, the caustic solution may be subjected to further treatment in order to remove the sulfur components therefrom and to regenerate the caustic for further use in the process.

4The gases containing phenols are Withdrawnv from extractor 28 through line 33 and valve 3l! to pump 35, whereby they` are directed through line `V36 and 'valve 37 to heater 38 provided with suitable heater means indicated at 39. In the case here illustrated, the gases are heated to a temperature of from about 300 to about 600 F., at a pressure of from about to 1000 pounds or more, and are directed through line 40 and Valve 4l to reactor A2. Reactor 42 may contain any suitable polymerization catalyst, a particularly preferred catalyst comprising an association of phosphoric acid and diatomaceous earth and generally referred to as solid phosphoric acid. In reactor 42, the olefinic gases will be in part polymerized to form polymers boiling Within the range of gasoline and in part reacted With the phenols to form alkylated phenols. It is understood that any suitable polymerization catalyst which also will effect alkylation of the phenols may be employed, including copper pyrophosphate, aluminum halides, as well as liquid acids such as sulfuric acid, phosphoric acid, hydrofluoric acid, etc. It is understood that when catalysts other than the solid phosphoric acid is employed, the operating conditions as well as the plant equipment will be modified accordingly.

The reaction products are withdrawn from zone 42 through line d3 and are directed through valve l into fractionator 45. Fractionator 45 similarly will contain heating means at the bottom and cooling means at the top, as well as contacting means therein such as bubble decks, trays, side to side pans, etc. Gases unconverted in reactor t2 are separated from polymer and alkylated phehols in fractionator and are withdrawn there? from through line 4t and valve il?. The polymer gasoline containing alkylated phenols is With` drawn from fractionator d5 through line d8 and valve 40. When desired, the polymers may be subjected to further fractionation to remove the y, high boiling polymers boiling above the range of gasoline. In a preferred embodiment of the invention, at least a portion of the causticV washed gasoline is directed from line 2l through line 50 and valve 5|, to be blended with the polymer gasoline, either before or after further fractionvention. operated to remove substantially all of the gases from the gasoline, and fractionator 5 may be operated as a stabilizer to produce a final gasoline blend of desired vapor pressure. In this embodiment gasoline in line 50 may be supplied to fractionator d5 by any suitable means, not illustrated. It is understood that other gas fractions containing oleiins, hydrogen sulfide and/ or light mercaptans, alone or together with the gases `from receiver 8, may be supplied to extractor 28.

The following example is introduced to illustrate further the noveity and utility of the present invention. but notv with the intention of unduly limiting the same.

Eran-ple A Midcontinent thermally cracked gasoline vmay contain 0.035% by weight of mercaptans,

0.03% by weight of phenols, and 500 grains of hydrogen sulfide per 100 cubic feet. The cracked gasoline is introduced into fractionator 2, which is operated as a stabilizer to remove overhead the light gases, including hydrogen sulfide and a suiiicient portion of the butanes and butylene, to leave a gasoline ofV the desired vapor pressure.

The stabilizer is operated at a pressure of about 250v pounds per square inch. The stabilized gasoline is treated in extractorY I9 with an aqueous caustic solution of about 25 Baume gravity at a temperature of about 85 F. and a pressure of about 25 pounds per square inch. The caustic solution from this extractor is supplied directly, without intermediate regeneration, to extractor :2% wherein it is utilized to treat the gases previously separated in receiver 8. Extractor 2B is operated at a temperature of about 85 F. and at a pressure of about 175 pounds per square inch. The hydrogen suliide contained in the gases from receiver 8 will displace the phenols absorbed from the gasoline in extractor i9. The gases in liquid phase containing phenols are heated in heater 38 to about 450 F. and are subjected to reaction in zone i2 at a pressure of about '700 pounds per square inch. The effluent products are fractionated in zone e5 to remove unconverted gases and to separate polymer containing alkylated phenols.

The previously7 caustic Washed gasoline is directed through line 5d and is blended in line 48 with the polymer gasoline containing alkylated phenols.

i claim as my invention:

l. A combination process which comprises treating gasoline containing phenolic compounds with an alkali metal hydroxide solution to remove the phenols from the gasoline and retaining the phenols in said solution, treating hydrocarbon gases containing more highly acidic components and olens under suicient pressure to maintain said gases in liquid phase, with said solution prior to the removal of phenols from the latter, Whereby said phenols are transferred from the solution to the gases, and subjecting said gases containing phenol and olens to reaction to form alkylated phenols and polymer.

2. A combination process which comprises treating gasoline containing phenols with an alkali metal hydroxide solution to remove the phenols from the gasoline and retaining the phenols in said solution, treating hydrocarbon gases containing hydrogen sulfide and olens under sufficient pressure to maintain said gases in liquid phase, with said solution prior to the removal of phenols from the latter, whereby said phenols are transferred from the solution to the gases, and subjecting said gases containing phenol to form alkylated phenol and oleiins to reaction and polymer.

3. A combination process which comprises treating cracked gasoline containing phenols with an alkali metal hydroxide solution to remove the phenols from the gasoline and retaining the phenols in said solution, treating cracked hydrocarbon gases containing hydrogen sulfide and olens with said solution prior to the removal of phenols from the latter, under suicient pressure to maintain said gases in liquid phase, whereby said phenols are transferred from the solution to the gases, and subjecting said gases containing phenols and oleflns to reaction in the presence of a polymerization catalyst to form polymer and alkylated phenol.

4. A combination process which comprises treating cracked gasoline containing phenols with a caustic solution to remove the phenols from the gasoline and retaining the phenols in the caustic solution, treating cracked hydrocarbon gases containing hydrogen sulde and oleiins with said caustic solution prior to the removal of phenols from the latter, under suiiicinet pressure to maintain said gases in liquid phase, whereby said phenols are transferred from the caustic solution to the liquefied gases, and subjecting said gases containing phenols and olefins to reaction in the presence of a polymerization catalyst to form polymer and alkylated phenols.

5. A combination process which comprises rractionating a mixture of gasoline and gases formed in the cracking of oil heavier than gasoline, separating in said fractionation a normally gaseous fraction containing normally gaseous olens and hydrogen sulfide and a gasoline fraction containing phenols, subjecting said gasoline fraction to treatment with an aqueous caustic solution under conditions to absorb phenols from said gasoline in said caustic solution, separately treating said normally gaseous fraction with the aqueous caustic solution containing phenols, without intermediate recovery of phenols from said caustic solution, and thereby displacing the phenols in said caustic solution by the hydrogen sulfide in said normally gaseous fraction, said treatment being under suii'icient pressure to maintain said normally gaseous hydrocarbons in substantially liquid phase, withdrawing from said last mentioned treatment a normally gaseous fraction containing phenols, subjecting said fraction to reaction in the presence of a phosphoric acid catalyst to polymerize a portion of the normally gaseous olens and to react another portion of the normally gaseous olefns with said phenols to form alkylated phenols, and recovering a polymer containing alkylated phenols.

6. The process of claim 5 further characterized in that the gasoline after treatment with caustic solution is combined with the polymer containing alkylated phenols to thereby produce a gasoline blend of improved oxidation stability.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,174,174 Greensfelder et al. Sept. 26, 1939 2,191,240 Stevens et al Feb. 20, 1940 

1. A COMBINATION PROCESS WHICH COMPRISES TREATING GASOLINE CONTAINING PHENOLIC COMPOUNDS WITH AN ALKALI METAL HYDROXIDE SOLUTION TO REMOVE THE PHENOLS FROM THE GASOLINE AND RETAINING THE PHENOLS IN SAID SOLUTION, TREATING HYDROCARBON GASES CONTAINING MORE HIGHLY ACIDIC COMPONENTS AND OLEFINS UNDER SUFFICIENT PRESSURE TO MAINTAIN SAID GASES IN LIQUID PHASE, WITH SAID SOLUTION PRIOR TO THE REMOVAL OF PHENOLS FROM THE LATTER, WHEREBY SAID PHENOLS ARE TRANSFERRED FROM THE SOLUTION TO THE GASES, AND SUBJECTING SAID GASES CONTAINING PHENOL AND OLEFINS TO REACTION TO FORM ALKYLATED PHENOLS AND POLYMER. 